Jetpack Compose navigate for result

Question

I'm using the Jetpack Navigation library with the Compose version. I'm setting up navigation like it's shown here

I want to be able to navigate from screen A to screen B. Once B does something and pops off the back stack, it will then return a result that screen A can access.

I found a way to do this using Activities here but I want to avoid creating any extra activities and do this in compose.

Answer 1

From the Composable that you want to return data, you can do the following:

navController.previousBackStackEntry
    ?.savedStateHandle
    ?.set("your_key", "your_value")
navController.popBackStack()

and then, from the source Composable, you can listen for changes using a LiveData.

val secondScreenResult = navController.currentBackStackEntry
    ?.savedStateHandle
    ?.getLiveData<String>("your_key")?.observeAsState()
...
secondScreenResult?.value?.let {
    // Read the result
}